Types | DnaRegion
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Roles | CDS
Coding
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Sequences | BBa_J36852_sequence (Version 1)
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Description
This part codes for the single-chain dimer of streptavidin protein, without the start codon. Streptavidin protein binds strongly to the biotin molecule, and can be used to bind biotinylated nucleic acids or peptides.
It was used as part of a fusion protein with lipoprotein signal peptide and outer membrane protein A transmembrane domains, to express streptavidin on the outer surface of E. coli. Streptavidin exists naturally as a tetramer, so this dimer form was attempted as a better binder of biotin than a monomeric form on the cell surface.
NOTE: According to sequencing, the SpeI site ACTAGT encountered a mutation to ATTAGT. Also, this part exists currently in pCR-Topo2.1 vector.
Notes
There was a PstI site CTGCAG at nucleotides 617-622 of the part, which was mutated to CTGCGG.
There are no spacer nucleotides between the part and the XbaI restriction site, or between the part and the SpeI restriction site, so that the mixed site would be 6bp long, and reading frame would be maintained between protein domains.
Source
PCR off a plasmid from Filiz Aslan at Boston University.